Well drilling equipment



J. H. SCHREIBE R WELL DRILLING EQUIPMENT April 4, 1950 2 Shets-Sheet 1 Filed July 2, 1945 R) s m. E e. m wvfl. m mm A J April 4, 1950 J. H. SCHREIBER 2,502,998

WELL DRILLING EQUIPMENT' Filed July 2; 1945 2 s nnnn s-Sheet 2 IN VEN TOR BY( f 'ATTO EY Patented Apr. 4, 1950 U NI TED IS TAT ES PATE N T OF F I CE WELL 3DRIILING EQUIPMENT John H. Schreiber, St/Louis, Mo. ii elican)n o-iilyz, 1945, serial'noxeo'a'vsv Cla'ims. l

co ms invention relates to well drilling equipment; and it has special "reference to a :cathead and joint breaker device or the type'used in the well drilling industry. v

The oathe'a'd proper oompris'es a spool Eremovably attached to one end of thei 'otar :drawworks shaft of a drilling rigifor constant rotation thereby when said shaitis rotating. fsaidrdrawworks shaft is rotated in one direction in jointbre'alting operations, but is -sometimes rotat'ed 'in the opposite direction in other operations. The joint bre'akeroomprises a drum th'atfis cooperatively associated. and combined with said oath'ead. The present invention .-is an improved modification of the invention disclosed-in Imy prior .application Serial No.-569, 7 02, 'filed December ZS, 194.4, for patent .for Well drilling equipment, and has the spool and the drum detachable from each other. As in said prior application, the joint breaker of the present invention co'mprls'esa shoe rigidly attached to one endof "a longitudinally movable and flexible Jerk line, "and one or :more pin-elements carried by the rotatin drum of th e joint' breaker iorengaging said-shoe-to movesaid jerk line longitudinally .in one direction to Ca greater extent than has heretofore :been possible in joint breakers of the type'in whi'c'h theipresent invention contained. :In attainingthese beneficial results, I provide a device having a :relatively small drum capable of eifectingza relatively longer movement of the flexible jerk line then has heretofore been possil'ole when saidjerkiline is under tension.

One object of the invention is to provide an improved oathead and joint breaker having a rotary drum for intermittently and optionally moving 'a flexible jerk line lon itudinally, oom-- prising ta .pair of axially alined removable *pins on said drum "for engaging :a "shoe attached to said jerk line, "formations on said drum functioning to support and prevent defiorrnation' of said pins, and releasable -elements :ior holding said pins in cooperative relationship and for preventin displacement'thereof.

other objects of the present invention iare' to provide an improved catlieadiand joint breaker haying ia removable pin, or a pair of longitudinally alined removable pins, for positively and pivotally engaging the jerk zline shoe to move-said jerk line longitudinally in one direction, and novel means removably holding-said pin :or pins in effective :p'osition on the rotary drum :so that, at the time desired, said pin or pins will'be engagedby the jerk z-line shoe and will move said shoe in ta planetary path about the axes of the 1' .2 drum in order to move said jerk line longitudinally in one direction; to provide devices for holding "and preventing displacement of said mespective removable pins While holding said .ipins separately :removable :from the "drum; to provide a pair of axially alined shoe engaginglremovalole pins mounted on the drum and separatedby an intervening space :for receiving the body portion of the shoe having laterally "extended lhookshaped flanges for positively andpivotally engag ing said *pins'; and to provide a :stationary cam enclosed within said drum for disengaging said shoe from said pins and thereby leaving thejerk line and the shoefre'e to move iandlreturntotheir initial Ester-ting positions while the drum continues to rotate.

Other objects and advantages will appeanfrom the following description, :reference beingmade to theannexed drawing, in which- :Fi'g. i is a longitudinal sectional view-10f my improved oathead andjoint breaker showing the jerk line shoe in position to be engaged by :two axially alined pins on the rotary drum of the joint breaker device.

Fig. 2 is a vertical cross 'sectional View taken approximately on the line '2-- 2 of :Fig. .1, and showin the jerk l-in'e shoe in the position to which it is moved by the controlling zsociret Iior engagement by' the pins on the rotating drum as'in Fig. 1.

Fig. 3 is an enlarged sectional view showing the inner end or one of the removable '"pins on the rotating drum for "engaging and operating the jerkline shoe to move the jerk line longitudinally, and also showing a "formation on said drum "functioning to support and prevent de-' formation of'said pin.

Fig. 4 is a sectional View on the line "4-4"o'f Fig. 3, showing one form of a device for holding one of the removable pins from displacement,

and also showing said formation for supporting and preventing deformation of-said pin.

Fig. '5 is av'iew showing a "modiiledform of device for holding one of the removable pins from displacement, and also showing in dotted lines said formation for supporting and preventing deformation of s'a' i'd'pin,

Fig. "6 is a sectional view on the line T6 56 or Fig. 5, showing additional features of said modified form .o'f'holding device for the removablepin.

Fig. '7 isa greatly enlarged view showingaportion of thelperipher of the rotary drum, (and also showing another -formof device for holding] the respective removable pins from displacement;

Fig. 8 is a similarly enlarged sectional view on the line 88 of Fig. 7.

The hollow cylindrical element I is designed and intended to be mounted on and attached to the usual rotary drawworks shaft for rotation thereby. Said element I is rotated in one direction by said shaft in joint-breaking operations, and in other operations is sometimes rotated in the opposite direction by rotation of said shaft in said opposite direction. Said element I constitutes a sleeve for receiving the end portion of the rotary drawworks shaft to which it is to be detachably Secured. Said sleeve I has a radial flange 2 integral with its inner end functioning as an abutment for one end member 3 of a bushing on which the hub 4 of the stationary housing 5 is supported, and also preventing longitudinal displacement of said housing. The other and complementary bushing member 8 is mounted on the outer end portion of said sleeve I and may be held from longitudinal displacement toward the bushing member 3 by the hub 4. The sleeve I has in its outer end a series of screwthreaded holes in which the studs I are secured. The hollow cylindrical cathead spool 8 has an inwardly extended flange 9 provided with unscrewthreaded holes through which said studs I project. Nuts III are screwed on the outer ends of the studs I and hold the spool 8 attached to the sleeve I for rotation thereby.

In the present construction, the rotary drum I I is separate from the cathead spool 8 and is rotatively mounted within the stationary housing 5, although said drum and spool may be integrally formed as disclosed in said prior application without departure from the principle of this invention. As shown, said drum II has a flange I2 extending inwardly against the outer end of the sleeve element I and provided with unscrewthreaded holes through which the studs 1 project. After the nuts I0 are tightened, said flange I2 of the drum II is held clamped between the flange 9 of the cathead spool and the outer end of the sleeve element I. Two axially alined and longitudinally spaced pins I3, constituting removable and replaceable elements for engaging the jerk line shoe, are secured on the drum II and are carried in a planetary orbit about the axis of the sleeve I and of the rotary drawworks shaft to which said sleeve is attached during rotation of said sleeve by said shaft.

' Repeated and intermittent contact and engagement of said pins I3 with the jerk line shoe (hereinafter described), and sliding disengagement of said shoe from said pins I3, has a tendency to Wear and to deform said pins I3. My present invention comprises elements attached to said drum engaging and holding the pins I3 in proper positions, and preventing longitudinal displacement thereof, and also facilitating removal and replacement of any worn or deformed pins I3 and replacement of unworn and undeformed pins in substitution for those that had become worn and deformed, and removed. My invention also comprises formations on the drum constituting mountings for said pins I3, and cooperating directly therewith, to prevent other deformation of said pins by said repeated contact and engagement of said pins with said brake shoe.

The two pins I3 are axially alined, are mounted in the respective side flanges I4 of the rotary drum I I, and are separated b an intervening Space I5. Said pins may be held from longitudinal displacement by releasable holders of different forms. As shown in Figs. 3 and 4, each pin I3 is formed with a circumferential groove I 6 receiving the two arms I! of a device in the form of a forked plate I8. The plates I8 are attached to the outer sides of the respective flanges I4 by removable screws I9 holding said devices II-I8 attached to the outer sides of said flanges I4 of the drum II to prevent longitudinal displacement of the pins I3, making it possible to mount said pins in any angular positions about their respective axes. The aforesaid formations on the drum which constitute mountings for said pins I3 and which prevent bending deformation of said pins by said repeated contact and engagement of said pins with said brake shoe, and the strains and stresses imparted by the jerk line, comprise arcuate shoulders I4a integral with the drum II and the two flanges I4 along the two adjacent corners formed by said drum and said flanges (Fig. 1). The said shoulders I4a are separated by a space having approximately the same width as said space I5 between said pins I3, so that the adjacent surfaces of said shoulders I4a are approximately flush with the adjacent ends of said pins I3. The forward ends of said two flanges I4a have bearing contact with and against rear and inner peripheral portions of the surfaces of said two pins I3, thereby preventing bending, shearing and analogous deformations of said pins I3 by repeated contact and engagement of said pins with the brake shoe hereinafter described, and the strains and stresses imparted by the jerk line. These are important features of the present invention. They very considerably prolong the durability or period of utility of the device, and they make possible repair of the joint breaker on the ground and in the field by removal and replacement of said pins I3 without long delay, as would necessarily occur in the case of joint breakers in which welding or other analogous repairs are required. These repairs which may be made without inconvenience and without long delay, and on the ground of operations, recondition the joint breaker as though the repaired damage had never occurred. The screws I9 are preferably secured to the plates I8 in a manner to prevent said screws from loosening after they have been tightened. As shown, pieces of wire Illa pass through holes in the heads of the respective screws I9 and through complementary adjacent holes in the plates I8 and thereby interlock said screws and said plates. This efiectively prevents the screws I9, the plates I8 and the pins I3 from becoming displaced after they have once been properly assembled.

Pins 20 may be used in substitution for the pins I3. Each pin 20 is preferably of hollow cylindrical form and provided with an internal annular cam 2I engaged by a spring arm 22. The cams 2I are between and inwardly from the ends of said pins, so that said pins may be reversed or initially mounted end for end without modifying their functions in any way. The spring arms 22 are formed integral with plates 23 attached to the outer sides of the respective side flanges I4 of the rotary drum II by detachable screws 24 having holes through their heads for receiving locking devices 25 to prevent accidental turning or loosening of said screws after said screws have been tightened. The plates 23 of the holders 22-23 engage against the outer ends of the respective pins 20 and positively prevent outward displacement of said pins, while the spring arms 22 engaging against the inner surfaces of the cams 2I prevent inward displacement of said pins 20, making it possible to mount said pins in escapes any angular positions about their respective axes. Eachp'in 20 has a groove 20a, or other formation, intermediate or its ends for engagement by :any suitable implement to move said pins longitudinallyi-n inward directions for purposes of removal and replacement. The pins 20 are of the same length as the pins I3, and cooperate with the ends ofthe formations Me in the same way asdo the pins I13.

.A jerk line 26 composed of wire rope or cable extends through a hole 21 in a shoe supporting and, operating member 28. Said member 28 is mounted on a pivot 29 carried by the stationary housing 5. A spring 30 connecting an arm 3I extending from the member .28 with :a rigid arm 32 projecting from the stationary housing :5, yieldingly holds said member28 in =its initial .unoperated position in which an extension 33 on said member engages and overlaps a part :34 on the stationary housing 5 untilsa'id member 28 is operated by the arm 3i. The jerk line shoe .shown is of the form disclosed in my said application Serial No. 569,702,1iled December 26, 1944, and is attached 'to the end of the jerk line 26 at the irmer end of the member 28. The body 35 of said shoe is of less thickness than the width of the space I5 between the adjacent ends of the pins I3 and 20, which is substantially equal to the distance between the arcuate shoulders Ma, so that said Shoe may be moved into said space I5 by the shoe engagingmemberZB to position in which said pins will engage the two .shoe hook flanges 36. The shoe body 35 cooperating with the arouate shoulders Ma, and the hook flanges 36 operating with the drum :flanges .IA, positively prevent turning displacement of the shoe va35-:3.6 atall times. Said shoe is thereby located and held at rest-in proper adjustment for movement by the member 28 to a position in which the'pins .13 .or the pins 20 will engage the :hooks 36 as described.

.A stationary cam 31 formed integral or rigid with the hub 4 of the stationary housing is engaged by the inner edge of the shoe body .35 at the .proper time during movement of said shoe body .by the pins I3 or 20. Said cam functions to move the shoe 35--36 outwardly far .enough to permit said pins to disengage and pass beyond the ends of the hook flanges 36 and thereby cooperate with the inherent and natural tendency of the wire rope or wire cable jerk line 26 to straighten and thus effect final disengagementof saidpins iromsaid hook flanges, leaving the jerk line 2.6 free to return the shoe 35-36 to its initial-orstartin position in the operatingmember 28. In order that the shoe body 35 :may move inwardly far enough to a position in which the pins I3 and 2!] may engage the shoe hooks 3.6, and .may then engage the stationary cam .31 to disengage said hook :flanges 36=from the pins I3 and 2.0, an arcuate slot 38 is formed in the drum II..

The said slot 38 extends entirely through the drum II. The stationary cam 31 is shownas an eccentric formation on the stationaryhub land has its high point approximately in contact with or close to the inner periphery of the drum I I and does .not interfere with or restrict the free rotation of said drum about said stationary hub 4. The drum M with its integral arcuate shoulders Ida prevent movement of the shoe 35-36 .by the 'member 28 far enough toward theaxis'of said drum to a position in which the pins I3 .and will engage the hooks 36 until the slot 38 is opposite and permits said movement 'of saidlshoe toward the axis of said drum. At the sides er the slot E38,; the arcuate shoulders 14a :are of reduced radial thickness in order not to prevent inward movement of the.shoe:--36 by obstructv ing the said shoe hooks 36. When the shoe'3536 is moved by the member 28 to position tolbe engaged :by the pins '13 or 20, said shoe extends through the slot 38 close to the periphery of the housing hub 4. After and while the hook flanges 36 are engaged by said pins, the shoe 35-36 is moved in a planetary course about the axis of the drum II and, after a predetermined extent of travel, the shoe body 35 engages and operates against the cam 31 and is thereby moved outwardly and disengaged from the pins I3 and 20, as described. Said pins are mounted near the rear end of the slot 38 so that the jerk line 26 will be 'wound on and about the drum I I during rotationof said drum. An inclined cam surface 39 is formed-on the drum I I at the opposite or rear end of the :slot 38 in order to engage and slide over the shoe 3536 and to prevent the drum from abutting against and damaging said shoe and other parts during reverse rotation of said drum,

as before mentioned. The housing 4- -5 is secured against rotation by attachment of an integral lug 40 as a stationary support, leaving the cathead and joint breaker free for rotation by the sleeve element I .and the shaft to which said element is attached. Said parts continue to rotate without operating the jerk line 26 until the engaging member 28 is moved in opposition to the tension of the spring 36 in order to move the shoe .35 into the slot 33 to a position for engagement of the pins i3 and 28 with the hook flanges 36 of said shoe. After the pins I3 and 2!] have engaged the hook flanges 36, the shoe will be moved with the rotating drum II, and the jerk line 26 will be wound on said drum until the hook flanges 36 are disengaged from the pins I3 and 28 by the cam'3'I, or otherwise.

Formation of the rotary drum Ii, etc., construction of the pins i3 and v26, and the releasable elements for holding said pins in cooperative relationship with each other and for preventing dis* placement :thereof, maybe varied in other'equivalent particulars without departure from the principle of .the invention. As shown enlarged in'l igs. '7 and 8, the drum I I may extend laterally beyond the outer sides of the two circumferential flanges M to provide edge margins 22, Bosses d2 are formed integral with the laterally extended margins it: and with the outer sides of the flanges I4, instead of being formed integral with the outer sides of said flanges only, as in the construction already described. Two axially alined pins d3, insubstitution for the two axially alined pins 13 and the two axially .alined pins 25, are mounted in holes provided for said pins through said bosses 42 and through the flanges it, the same as the pins I3 and 2d The two axially alined pins 43 are separated by an intervening space :I-5,.a-s are the two :pins I3 and the two pins 20. The pins 43 have their inner ends approxtmately flush with the adjacent surfaces of the forward ends of theformations on the shoulders I ia against which the rear and inner peripheral surfaces of said pins bear and abut, leaving the front and inner peripheral surfaces of said pins 43 exposed .for engagement by the hook flanges 35. The outer ends of said pins 43 are approximately flush with the outer surfaces of the bosses 42, so that the :length of each of said pins is approximately equal to the combined thidkness of the boss "42, flange I l and formation on the shoulder ite in :agamst which said pins respectively secured for engagement by the hook flanges 36 of the shoe 35-36.

Annular slots 44 extend from the respective holes in which the pins 43 are mounted to the peripheral surfaces of the flanges l4 and bosses 42 providing tongue devices 45 attached to the drum II for engaging and holding the pins 43 from displacement in any direction. Screws 46 extend through holes in the devices 45 and have screwthreaded engagement in screwthreaded holes 41 inwardly beyond said devices 45 for securely bending and clamping said devices 45 on the pins 43 to hold said pins from displacement in any direction. The heads 48 of the screws 48 are received and contained in recesses 49 formed in the bosses 42 and flanges [4. After the respective screws 46 are tightened, and after the elements 45 are thereby bent in opposition to their inherent resiliency and engaged with and hold the pins 43 from displacement, the metal around the open ends of the holes 49 is peened or otherwise deformed to provide inturned formations 50 clampingly engaging the screwheads 48 and thereby holding the screws 45 from turning and loosening. The devices 45 are thus held in engagement with and prevent displacement of the pins 43. When it is desired to remove any pin 43 for replacement or other purposes, it is only necessary to remove the formation 50, manually loosen the screw 46, and permit the device 45 to spring outwardly, releasing and permitting removal and replacement of said pin 43. After any pin 43 has been removed, another similar pin may be substituted therefor, the screw 46 tightened to clamp the device 45 against the newly substituted pin 43, and another formation 50 peened to prevent the screw 46 from turning and loosening.

The operation of my improved joint breaker, or combined cathead and joint breaker, is evident to one skilled in the art to which it appertains from the foregoing description. My invention attains all of its objectives and purposes efficiently and economically and provides means whereby any worn or damaged pins I3 and 20 may be conveniently removed and replaced when needed to recondition the device for further use and operation. In this invention, as in the invention disclosed in my copending application Serial No. 569,702, I utilize a cathead having a relatively small drum 1 l capable of effecting a longer stroke of the jerk line than has heretofore been pcssible by use of joint breakers of this type. It is apparent that other specific variations than those specifically disclosed may be made in the construction and arrangement of the parts as do not depart from the nature and principle of the invention as defined by the appended claims.

I claim:

1. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; flanges integral with said drum forming a circumferential space around said drum for said shoe, a pair of axially alined pins extending through said flanges into said space for engaging said shoe to move said jerk line longitudinally as aforesaid, and formations on said drum engaging the rear and inner peripheral surface portions of said pins.

2. In a joint breaker having a rotary dnum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; a pair of circumferential flanges integral with said drum and separated by an intervening space for containing said shoe, two axially alined removable pins extending through said flanges and having their adjacent ends separated by an intervening space for receiving the body of said shoe, hooks integral with said shoe for engagement by said pins to move said shoe with said drum and thereby move said jerk line longitudinally as aforesaid, and shoulders integral with said drum and said flanges engaging the rear and inner circumferential portions of said pins and preventing deformation of said pins by said hooks.

3. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; a pair of circumferential flanges integral with said drum and separated by an intervening space for containing said shoe, two axially alined removable pins extending through said flanges and having their inner ends separated by an intervening space for receiving the body of said shoe, hooks integral with said shoe for engagement by said pins to move said shoe with said drum and thereby move said jerk line longitudinally as aforesaid, shoulders integral with said drum and said flanges engaging the rear and inner circumferential portions of said pins and preventing deformation of said pins by said hooks, and releasable elements attached to said drum engaging and holding said pins from displacement.

4. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; a pair of circumferential flanges integral with said drum and separated by an intervening space for containing said shoe, two axially alined removable pins extending through said flanges and having their axes parallel with the axis of said drum and also having their inner ends separated by an intervening space for receiving the body of said shoe, hooks integral with said shoe for engagement by the forward and outer peripheral portions of said pins to move said shoe with said drum and thereby move said jerk line longitudinally as aforesaid, arcuate shoulders integral with said drum and said flanges engaging the rear and inner circumferential portions of said pins and preventing deformation of said pins by said flanges, elements engaging and holding said pins from longitudinal displace ment, and screws attaching said elements to said drum.

5. In a joint breaker having a rotary drum provided with an elongated slot extending circumferentially, a stationary support on which said drum is mounted for rotation, a stationary cam rigid with said support within said drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; flanges integral with said drum forming a circumferential space around said drum for containing said shoe, a pair of axially alined pins extending through said flanges into said space rearwardly beyond the forward end of said slot for engaging said shoe when said shoe is extended through said slot, means for moving said shoe from a position beyond said drum to a position in which said shoe extends into said slot for engagement by said pins, and a stationarycam enclosed within. said'drunr forcontacting and disengaging: said shoe" from. said. pins during rotation. of said. drum.

6. In a joint breaker having a rotary drum providediwith a slot extending circumferentially, a. longitudinally movable jerk line; a shoe attached to said. jerk line for operation. by said drum to movesaid jerk line longitudinally in one direction, and a stationary? cams supported. within said rotary: drum; two axially alined removable pins supported by said drumrearwardly beyond the forward end of said slot and having their adjacent ends separated by an: intervening space for." receiving thev body at said shoe" when said shoe is extended-through said? slot, hooks integral with said shoe for engagement by said pins to move said shoe withrsaid' drum and thereby move said jerk line longitudinally as aforesaid, and shoulders integral with said drum separated by an intervening space receiving the body of'saidshoe and engaging the rear and inner circumferential portions of-"said pins to prevent deformation of said pins by said shoe and. by'said hooks.

7'. In a joint breakerhaving a rotary drum provided with a circumferential slot; a longitu dinally movable jerk line; a shoe attached to said jerk line for operation to move said jerk line longitudinally in one direction during rotation of said drum, and a pair ofhooks integral with said shoe; two axially alined removable pins supported by said drum and havingtheir inner ends separated by an intervening space for receiving said shoe and for engaging said hooks to move said shoe with. said drumand therebymove said jerk line longitudinally as aforesaid when said shoe extends into said slot, means for moving saidishoe. toalposition in. which said shoe extends into said slot, formations on said drum engaging the rear and inner circumferential portions of said pins and preventing deformation of said pins by said hooks, and releasable elements attachedto said drum holding said pins fromdisplacement.

8. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for movement in a planetary orbit about the axis of" said drum to move said jerk line longitudinally inone direction; a pair of axially alined pins supported by said drum and separated by an intervening space for receiving said shoe, formations integral with said drum engaging the rear and inner peripheral surface portions of said pins and leaving the forward and outer peripheral portions or said pins exposed for engagement with said shoe, hooks on said shoe for engaging said forward and outer exposed portions of said pins forwardly and outwardly beyond said formations, and a device for supporting said shoe out ,of position in which said pins will engage said hooks and for moving said shoe to a position in which said pins will engage said hooks during rotation of said drum.

9. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for movement in a planetary orbit about the axis of said drum to move said jerk line longitudinally in one direction; a pair of axially alined pins supported by said drum and separated by an intervening space for receiving said shoe, formations integral with said drum engaging the rear and inner peripheral surface portions of said pins and leaving the forward and outer peripheral portions of said pins exposed for engagement with said shoe, hooks on said shoe for engaging said' forward and outer exposed portions of said pins forwardly and out wardly beyond said formations, a device for supporting said shoe out of position in which said pins will engage said hooks and for moving said shoe to a position in which said pins will engage saidv hooks during rotation of'said drum, members engaging'and holding said pins from longitudina-l displacement in either direction, and de tachable elements secured to said drum holding said members in rigid connection with said drum.

10. In a joint breaker having a rotary drum provided with anelongated circumferential slot, a stationary support about which said drum is mounted for rotation, a rotary device within said support for'rotatingsaid' drum,- a stationary cam' rigid with: said support inside said drum, a Iongitudinally movable jerk line, and a shoe at tached. to said jerk line for movement in a planetary path above the axis of said drum to movesaid jerk line longitudinally in one direction; a pair of axially alined pins supported by said drum adj acent to the rear end of said slot, mech-- anism for-moving said shoe into said slot for en gagem'ent" by the forward and outer circumferential portions of said pins, and formations integral' with said drum engaging the inner" and? rear peripheral? portions of said pins inwardly and rearwardly beyond-said first-named portions of said pins that engage said shoe.

11. In a joint breaker having a rotary drum; a longitudinally movable jerk line, and a shoe' at tached to said jerk line for operation by said" drum to moversaid jerkline longitudinally in one direction; a removable pin supported: by: and" movable with saiddrumfor engaging said shoe to move said jerk line longitudinally as aforesaid, said pin. being symmetrical so that it: can be turned end for end to equalize the wear on: its surface', and. adev-icezattached to said drum engaging and: holding said pin from longitudinal displacement in either direction-..

12; In a joint breaker having a rotary drum; a longitudinally movable: jerk. line,. and a shoe. attached to said? jerk line for operation by said! drum to move said jerk line longitudinally in; onedirection; a rotatable pinl supported by and having a portion: thereof extending permanently." beyond the periphery of said drum for engaging said shoe to move said jerk line longitudinally while said drum is rotating, and a device attached to said drum engaging and holding said pin from longitudinal displacement and leaving said pin rotative relative to said drum and said device.

13. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; two removable pins supported by and movable with said drum and separated by an intervening space for receiving said shoe, means for moving said shoe into said space for engagement by said pins to move said jerk line longitudinally while said drum is rotating, and devices attached to said drum engaging and holding said respective pins from longitudinal displacement.

14. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; two axially alined rotatable pins supported by and movable with said drum and separated by an intervening space for receiving said shoe, manipulative means for moving said shoe into said space between said pins, parts on said shoe for engaging said pins when said shoe is in said space and moving said jerk line longitudinally, and elements attached to said drum engaging and holding said respective pins from longitudinal displacement and leaving said pins rotative relative to each other and relative to said drum.

15. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe-attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; a pair of axially alined pins supported by and movable with said drum for engaging said shoe to move said jerk line longitudinally as aforesaid, each of said pins having a circum- Ierential groove outside of said drum, and an element attached to said drum and engaging in said groove to hold said pin from longitudinal displacement in either direction.

16. In a joint breaker having a rotary drum. a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; a pair of axially alined pins supported by and movable with said drum for engaging said shoe to move said jerk line longitudinally as aforesaid, each of said pins having a circumferential groove outside of said drum, and an element attached to said drum and engaging in said groove to hold said pin from longitudinal displacement in either direction and leaving said pin rotative relative to said drum and said element.

17. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; a hollow pin supported by and movable with said drum for engaging said shoe to move said jerk line longitudinally as aforesaid, a cam integral with the inside of said shoe, and a spring device attached to said drum and extending into said pin engaging said cam and holding said pin from longitudinal displacement.

18. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; two axially alined pins supported by and movable with said drum and separated by an intervening space for receiving said shoe and each of said pins having a circumferential groove at the outer side of said drum, elements attached to said drum engaging in said grooves and holding said pins from longitudinal displacement, and means for moving said shoe into said space for engagement by said pins.

19. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction; two axially alined hollow pins supported by and movable with said drum and separated by an intervening space for receiving said shoe, means for moving said shoe into said space for engagement by said pins to move said jerk line longitudinally as aforesaid, spring devices attached to said drum extending into said respective pins, and formations in said respective pins engaged by and cooperating with said spring devices for holding said respective pins from relative and other longitudinal displacement.

20. In a joint breaker having a rotary drum, a longitudinally movable jerk line, and a shoe attached to said jerk line for operation by said drum to move said jerk line longitudinally in one direction, a pair of axially alined pins supported by and movable with said drum for engaging said shoe to move said jerk line longitudinally as aforesaid, and formations on said drum engaging the rear and inner peripheral surface portions of said pins to prevent deformation of the same.

JOHN H. SCHREIBER.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,070,326 Contant et al Aug. 12, 1913 1,713,586 Wright May 21, 1929 2,182,292 Guier Dec. 5, 1939 2,314,733 Owen Mar. 23, 1943 

